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United States Patent | 5,150,016 |
Sawase ,   et al. | September 22, 1992 |
An LED light source with readily adjustable luminous energy including LED chips is disclosed. A resistor device is provided in order to control the current flowing in LED chips for reducing variance of luminous energy. The resistor device includes a plurality of resistors arranged in parallel, and a plurality of fuses connected in series with the respective resistors. In order to obtain the desired resistance value of the resistor device, the fuses connected to unnecessary resistors in series are burnt out by applying an excess current to the fuses thereby omitting a bonding process of the resistors or the like.
Inventors: | Sawase; Kensuke (Kyoto, JP); Ogata; Hiromi (Kyoto, JP) |
Assignee: | Rohm Co., Ltd. (Kyoto, JP) |
Appl. No.: | 763289 |
Filed: | September 20, 1991 |
Sep 21, 1990[JP] | 2-253405 | |
Sep 21, 1990[JP] | 2-253406 | |
Dec 26, 1990[JP] | 2-406620 |
Current U.S. Class: | 315/294; 257/E25.02; 315/185R; 315/189; 315/192; 362/800 |
Intern'l Class: | H05B 037/00 |
Field of Search: | 315/294,291,179,180,185,189,192,312,58 362/800,295 307/202.1 |
4231079 | Oct., 1980 | Heminover | 362/800. |
4329625 | May., 1982 | Nishizawa et al. | 315/192. |
4412241 | Oct., 1983 | Nelson | 307/202. |
4686384 | Aug., 1987 | Harvey et al. | 307/202. |
4810937 | Mar., 1989 | Havel | 315/158. |
4939426 | Jul., 1990 | Menard et al. | 315/192. |
4947291 | Aug., 1990 | McDermott | 362/800. |
5058059 | Oct., 1991 | Matsuo et al. | 307/202. |
Foreign Patent Documents | |||
0050117 | Apr., 1980 | JP | 315/192. |